Fixed a critical bug in the runtime, where _d_allocmemoryT would mark the memory block as having pointers (for scanning) opposite of what it should. So pointers would not be seen and freed. Should fix a bunch of regressions with AAs.

module structs7;

struct S
{
    int i;
    long l;
}

void main()
{
    S s = void;
    int i = s.i;
    long l = s.l;
}